1. Field of the Invention
The invention relates in general to the automatic inspection of objects and in particular to an apparatus and method for inspecting labelled bottles.
2. Description of the Prior Art
In many industries, it is necessary to determine if an object conforms to a predetermined standard. For example, when a label is applied to a package or a container, it is desirable to know that the label was placed in the proper area and that the label has no defect such as a printing error or a tear. Such information is especially important in a process where the labels are automatically applied such as the in-mold labelling of bottles.
Typically, systems for inspecting labelled bottles utilize a photo-sensitive diode array or a television camera to generate signals representing the brightness or intensity levels of the labelled surface. These signals can then be compared with a standard or reference pattern in order to detect missing labels, printing errors, flaws, etc. The standard or reference pattern can be an "ideal" with a set of tolerances or a pattern which has been "learned" by inspecting a number of "good" bottles.